Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [PATCH] powerpc: Remove the static variable initialisations to 0 | Date | Mon, 25 Jul 2022 13:27:52 +1000 |
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Segher Boessenkool <segher@kernel.crashing.org> writes: > On Sat, Jul 23, 2022 at 03:34:05PM +0200, Michal Suchánek wrote: >> Hello, >> >> On Sat, Jul 23, 2022 at 05:24:36PM +0800, Jason Wang wrote: >> > Initialise global and static variable to 0 is always unnecessary. >> > Remove the unnecessary initialisations. >> >> Isn't this change also unnecessary? >> >> Initializing to 0 does not affect correctness, or even any kind of >> semantics in any way. > > It did make a difference when the kernel was still compiled with > -fcommon (which used to be the GCC default on most configurations, it is > traditional on Unix). No explicit initialiser puts an object in .bss if > you use -fcommon. This matters a bit for data layout.
The kernel has built with -fno-common since ~2002.
I think the belief is that an explicit initialiser of 0 forces the variable into .data, but AFAICS that is not true with any compiler we support.
cheers
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